From 996a9006d3f101dc5c48b58339e2e7323040fd59 Mon Sep 17 00:00:00 2001 From: Stefan Kerkmann Date: Tue, 4 Oct 2022 23:10:24 +0200 Subject: [Core] PWM Backlight for RP2040 (#17706) --- quantum/backlight/backlight_chibios.c | 51 ++++++++++++++++++++--------------- 1 file changed, 30 insertions(+), 21 deletions(-) (limited to 'quantum/backlight/backlight_chibios.c') diff --git a/quantum/backlight/backlight_chibios.c b/quantum/backlight/backlight_chibios.c index e8f9e70f78..30e95bd5c8 100644 --- a/quantum/backlight/backlight_chibios.c +++ b/quantum/backlight/backlight_chibios.c @@ -40,16 +40,22 @@ # endif #endif -static PWMConfig pwmCFG = {0xFFFF, /* PWM clock frequency */ - 256, /* PWM period (in ticks) 1S (1/10kHz=0.1mS 0.1ms*10000 ticks=1S) */ - NULL, /* Breathing Callback */ - { /* Default all channels to disabled - Channels will be configured durring init */ - {PWM_OUTPUT_DISABLED, NULL}, - {PWM_OUTPUT_DISABLED, NULL}, - {PWM_OUTPUT_DISABLED, NULL}, - {PWM_OUTPUT_DISABLED, NULL}}, - 0, /* HW dependent part.*/ - 0}; +#ifndef BACKLIGHT_PWM_COUNTER_FREQUENCY +# define BACKLIGHT_PWM_COUNTER_FREQUENCY 0xFFFF +#endif + +#ifndef BACKLIGHT_PWM_PERIOD +# define BACKLIGHT_PWM_PERIOD 256 +#endif + +static PWMConfig pwmCFG = { + .frequency = BACKLIGHT_PWM_COUNTER_FREQUENCY, /* PWM clock frequency */ + .period = BACKLIGHT_PWM_PERIOD, /* PWM period in counter ticks. e.g. clock frequency is 10KHz, period is 256 ticks then t_period is 25.6ms */ +}; + +#ifdef BACKLIGHT_BREATHING +static virtual_timer_t breathing_vt; +#endif // See http://jared.geek.nz/2013/feb/linear-led-pwm static uint16_t cie_lightness(uint16_t v) { @@ -60,10 +66,11 @@ static uint16_t cie_lightness(uint16_t v) { // to get a useful result with integer division, we shift left in the expression above // and revert what we've done again after squaring. y = y * y * y >> 8; - if (y > 0xFFFFUL) // prevent overflow + if (y > 0xFFFFUL) { // prevent overflow return 0xFFFFU; - else + } else { return (uint16_t)y; + } } } @@ -85,6 +92,7 @@ void backlight_init_ports(void) { backlight_set(get_backlight_level()); #ifdef BACKLIGHT_BREATHING + chVTObjectInit(&breathing_vt); if (is_backlight_breathing()) { breathing_enable(); } @@ -92,7 +100,9 @@ void backlight_init_ports(void) { } void backlight_set(uint8_t level) { - if (level > BACKLIGHT_LEVELS) level = BACKLIGHT_LEVELS; + if (level > BACKLIGHT_LEVELS) { + level = BACKLIGHT_LEVELS; + } if (level == 0) { // Turn backlight off @@ -115,20 +125,19 @@ void backlight_task(void) {} */ static const uint8_t breathing_table[BREATHING_STEPS] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 17, 20, 24, 28, 32, 36, 41, 46, 51, 57, 63, 70, 76, 83, 91, 98, 106, 113, 121, 129, 138, 146, 154, 162, 170, 178, 185, 193, 200, 207, 213, 220, 225, 231, 235, 240, 244, 247, 250, 252, 253, 254, 255, 254, 253, 252, 250, 247, 244, 240, 235, 231, 225, 220, 213, 207, 200, 193, 185, 178, 170, 162, 154, 146, 138, 129, 121, 113, 106, 98, 91, 83, 76, 70, 63, 57, 51, 46, 41, 36, 32, 28, 24, 20, 17, 15, 12, 10, 8, 6, 5, 4, 3, 2, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}; -void breathing_callback(PWMDriver *pwmp); +static void breathing_callback(virtual_timer_t *vtp, void *p); bool is_breathing(void) { - return pwmCFG.callback != NULL; + return chVTIsArmed(&breathing_vt); } void breathing_enable(void) { - pwmCFG.callback = breathing_callback; - pwmEnablePeriodicNotification(&BACKLIGHT_PWM_DRIVER); + /* Update frequency is 256Hz -> 3906us intervals */ + chVTSetContinuous(&breathing_vt, TIME_US2I(3906), breathing_callback, NULL); } void breathing_disable(void) { - pwmCFG.callback = NULL; - pwmDisablePeriodicNotification(&BACKLIGHT_PWM_DRIVER); + chVTReset(&breathing_vt); // Restore backlight level backlight_set(get_backlight_level()); @@ -139,7 +148,7 @@ static inline uint16_t scale_backlight(uint16_t v) { return v / BACKLIGHT_LEVELS * get_backlight_level(); } -void breathing_callback(PWMDriver *pwmp) { +static void breathing_callback(virtual_timer_t *vtp, void *p) { uint8_t breathing_period = get_breathing_period(); uint16_t interval = (uint16_t)breathing_period * 256 / BREATHING_STEPS; @@ -150,7 +159,7 @@ void breathing_callback(PWMDriver *pwmp) { uint32_t duty = cie_lightness(rescale_limit_val(scale_backlight(breathing_table[index] * 256))); chSysLockFromISR(); - pwmEnableChannelI(pwmp, BACKLIGHT_PWM_CHANNEL - 1, PWM_FRACTION_TO_WIDTH(&BACKLIGHT_PWM_DRIVER, 0xFFFF, duty)); + pwmEnableChannelI(&BACKLIGHT_PWM_DRIVER, BACKLIGHT_PWM_CHANNEL - 1, PWM_FRACTION_TO_WIDTH(&BACKLIGHT_PWM_DRIVER, 0xFFFF, duty)); chSysUnlockFromISR(); } -- cgit v1.2.3